What Is an Aircraft Starter Generator

In modern aviation, having reliable, space-saving components is essential for achieving optimized performance throughout flight operations. Among the many parts that support this goal is the aircraft starter generator, a hybrid component that facilitates engine start-up processes while also generating power for onboard systems. Understanding its design, functions, and importance is important for aircraft operators and maintenance professionals alike, so read on as we provide an overview.

What Does an Aircraft Starter Generator Do?

Aircraft starter generators are commonly found in aircraft with gas turbine generators, where they serve two primary purposes.

1. Engine Starting: Aircraft starter generators are useful for converting electrical energy into mechanical motion that can crank an engine until it reaches self-sustaining operations.
2. Power Generation: Once an engine is running, starter generators then switch to producing electrical power for the benefit of avionics, lighting, and other onboard systems.

This dual-role design makes them indispensable, especially where efficient weight and space usage is critical. For smaller piston-engine aircraft, direct cranking electric starters are more common due to the differing operational requirements.

The Functional Phases of a Starter Generator

To better understand the two primary roles of a starter generator, it is best to break down the basic elements of each phase.

Start Mode

1. To begin, the starter generator receives electrical power from a battery or auxiliary power unit (APU).
2. This allows the generator to begin producing torque to rotate the engine shaft.
3. Rotation initiates fuel ignition and engine self-sustainment, concluding the starting phase of operations.

Generator Mode

1. After start-up, internal systems reconfigure to prepare for generator mode.
2. At this point, the unit begins producing electricity.
3. Connected to the wider electrical system, this energy powers aircraft systems with regulated voltage and current.

This seamless transition between modes is what makes the starter generator so effective in aviation environments.

Common Construction and Design Elements

Aircraft starter generators are complex apparatuses, housing four main types of field windings that enable their mode switching capabilities:

• C Field: This field winding is only active during engine starting operations.
• Shunt Field: The shunt field operates in generator mode.
• Compensating Field: This winding assists with voltage regulation.
• Interpole or Commutating Winding: Such field winding is important for aiding in current reversal and reducing arcing.

During startup, all but the shunt field are energized in series with the source. When acting as a generator, the C field disengages, and the shunt, compensating, and interpole windings then act to ensure stable power output.

Why Are Starter Generators Essential?

• Space and Weight Savings: One device performs two roles, reducing the amount of technology present in the aircraft.
• Power Efficiency: Starter generators reduce overall loads on aircraft systems with their multitasking capabilities.
• Operational Reliability: Starter generators reduce the chance of experiencing failure during engine startup and in-flight operations.

Even without accounting for other benefits, starter generators notably combine functionality and efficiency in a way that aligns perfectly with the demanding needs of modern aviation operations.

General Maintenance Requirements for Starter Generators

To keep starter generator systems running optimally, periodic checks are essential. While practices will generally vary based on the type of equipment one uses and manufacturer recommendations, the following are common elements:

• Inspecting Brushes and Replacing Worn Components
• Checking Commutators for Pitting or Damage
• Lubricating Bearings as per Maintenance Schedules
• Testing for Voltage and Current Consistency

Ignoring these elements can lead to reduced efficiency, electrical faults, or total component failure.

How to Select the Right Starter Generator Parts

When sourcing a new or replacement unit, as well as parts for such equipment, always be sure to consider:

• OEM Compatibility
• Certified Part Numbers and Serial Tracking
• Manufacturer Reputation and Documentation

These factors can help one ensure compliance, performance, and safety across their fleet.

ASAP Components as a Source for Starter Generator Parts and Beyond

ASAP Semiconductor is proud to offer customer’s access to a wide range of high-quality starter generators, windings, and associated aircraft components through ASAP Components. Here, customers can access a plethora of competitively priced options that are sourced from leading manufacturers and suppliers across the globe, as well as benefit from hands-on service provided by our staff. To experience all that we have to offer, be sure to get in touch with us today via phone, email, or an online RFQ form submission.